摻鎂鈮酸鋰晶體周期極化及其光學(xué)參量振蕩研究.pdf

1、摘要摘要摻鎂妮酸理晶體與同成分妮酸鏗晶體相比，抗光折變能力顯著增強(qiáng)，因而它在非線性光學(xué)頻率變換領(lǐng)域有著更廣泛的應(yīng)用前景。本文研究了摻鎂妮酸銼晶體的周期極化特性，并對(duì)周期極化摻鎂妮酸銼晶體開(kāi)展了倍頻和光學(xué)參量振蕩的實(shí)驗(yàn)研究工作。本文的主要內(nèi)容有:介紹了周期極化摻鎂妮酸銼晶體準(zhǔn)相位匹配倍頻和光學(xué)參量振蕩研究的研究現(xiàn)狀簡(jiǎn)要介紹了準(zhǔn)相位匹配技術(shù)的原理。介紹了我們制備周期極化摻鎂妮酸理晶體的實(shí)驗(yàn)方法。研究了摻鎂妮酸銼晶體的極化過(guò)程和極化特性。對(duì)不

2、同濃度摻鎂妮酸鉀晶體極化反轉(zhuǎn)進(jìn)行了實(shí)驗(yàn)研究，發(fā)現(xiàn)隨著摻鎂濃度的增多，極化反轉(zhuǎn)電場(chǎng)降低，摻5mo1鎂泥酸w晶體的極化反轉(zhuǎn)電場(chǎng)僅為3kVmm并對(duì)反轉(zhuǎn)電場(chǎng)降低的原因進(jìn)行了詳細(xì)的分析解釋。利用制備的厚度為Imm，周期為7.0Ftm的周期極化摻鎂妮酸鏗晶體進(jìn)行了倍頻研究。在室溫下，輸入功率為75mW時(shí)，得到了3.5mW的倍頻532nm的綠光輸出，轉(zhuǎn)換效率為4.6%e利用聲光調(diào)QNd:YV04固體激光器直接泵浦PPMgLN晶體，開(kāi)展了準(zhǔn)連續(xù)納秒OP

3、G的研究工作。輸入3W的泵浦光時(shí)，得到信號(hào)光的輸出功率為44mW，轉(zhuǎn)換效率為1.5%0我們重點(diǎn)對(duì)PPMgLNOPO進(jìn)行了實(shí)驗(yàn)研究。使用周期為30pm的PPMgLN在室溫下得到低閉值、高轉(zhuǎn)換效率的1503nm信號(hào)光輸出，輸出功率為36mW通過(guò)溫度調(diào)諧，得到了穩(wěn)定的1503nm1550nm波段信號(hào)光輸出。在溫度為180℃時(shí)，信號(hào)光輸出功率為47mW實(shí)際轉(zhuǎn)換效率為209%.報(bào)道了PPMgLN的周期調(diào)諧實(shí)驗(yàn)結(jié)果，周期調(diào)諧(2931tm)與溫度調(diào)

4、諧(301800C)相結(jié)合，得到了穩(wěn)定的14451685nm的無(wú)重疊連續(xù)可調(diào)諧寬波段輸出。詳細(xì)分析了幾個(gè)參考文獻(xiàn)中摻鎂泥酸鑊晶體折射率的不同，根據(jù)本文摻鎂妮酸銼晶體準(zhǔn)相位匹配光學(xué)參量振蕩輸出信號(hào)光波長(zhǎng)實(shí)驗(yàn)結(jié)果，對(duì)AbstractMgO(5mol%)dopedLiNb03crystalisanimportantmaterialfornonlinearopticalapplicationbecauseithasahigherresistan

5、cetophotorefractivethandoesLiNb03.InthisdissertationweresearchedtheperiodicallypolingcharacteristicsofMgO:LiNbO3wemadesomeexperimentsonsecondharmonicgeneration(SHG)andopticalparametricoscillatorbyusingperiodicallypoledMg

6、OdopedLiNb03(PPMgLN)Themaincontentofthisdissertationareasfollowing:1.WeinvestigatedthecurrentevolvementonquasiphasematchedSHGandOPOinPPMgLNAndthequasiphasematchedtheoryisintroducedsimply.2.ThetechniqueoffabricatingPPMgLN

7、wasdescribed.WestudythethepolingcharacteristicsofthedopingdiferentlevelsMgOLiNb03theswitchedfielddecreasedwiththeincreasingofdopingMgOlevel.Thedoping5mol%PPMgLNwasrealizedusing3kVmmfield.Andthedecreasereasonwasexplainedw

8、hichbasedontheLivacancymodel3.Theperiodicallypoledgratingwassuccessfullyfabricatedin1.OmmthickMgO:LiNbO3.SecondharmonicgreenlightgenerationinPPMgLNwasdemonstrated.Thegreenlightpowerof3.5mWat532nmwasobtainedwhenthefundame

9、ntalpowerwas75mWandtheconversioneficiencyis4.6%4.Wereportahighrepetitionrateopticalparametricgeneration(OPG)basedonPPM沙Npumpedby1064nmNd:YAGlaser.Wegained44mWoutputpowerofsignalwaveandidlerwaveandtheconversioneficiencyis

10、1.5%5.Atroomtemperaturethe36mWsignaloutputisgainedusingPPMgLNwiththeperiodof30pm.Andthesignaloutputfrom1503to1550nmbytuningthetemperaturefromroomtemperatureto1800C.Additionallythesignaloutputis47mWandtheactuallyconversio